In recent discussion on the development of National Basic Livelihood Security System(NBLS), the main issue has been how to eradicate the blind spot of the system. One of the promising answer to that problem is the change of benefit system of NBLS, from comprehensive system to separate one. Based on the new policy report published by Unit for improving Anti-poverty Program, this study tried to estimate the effect of the reformation of NBLS benefit system, using Koweps data(6th wave). According to our estimation, about 3.9 to 4.2% of all households could be the recipients of living cash benefit, and 6.5 to 11.8% households could be covered by housing benefit. The households covered by medical benefit as well as medical expenditure assistance program would be increased by 24.5%. And the ratio of households covered by at least one of these three benefits would by 27.3%, which is almost four times as current ratio, 6.9%. Most of newly covered group by reformed NBLS benefit system would be the vulnerables, such as the aged, the unemployed, temporary employees, and those who are not covered by social insurances. (The rest is ommitted)